Systems and methods for signal frequency division in wireless communication systems

ABSTRACT

A system may include at least one antenna for receiving a first receive signal having a first signal diversity property and a second receive signal having a second signal diversity property. A first signal path may include a first frequency converter for downconverting the first receive signal to a first intermediate frequency signal having a first intermediate frequency. A second signal path may include a second frequency converter for downconverting the second receive signal to a second intermediate frequency signal having a second intermediate frequency. A transducer module may route the first receive signal to the first signal path, and route the second receive signal to the second signal path. A first N-plexer may select the first intermediate frequency signal or the second intermediate frequency signal for transmission to a cable, and to provide a data signal based on a selected intermediate frequency signal to the cable.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/639,328, filed Mar. 5, 2015 and entitled “Systems andMethods for Signal Frequency Division in Wireless CommunicationSystems,” now U.S. Pat. No. 9,350,437, which is a continuation of U.S.patent application Ser. No. 13/654,294, filed Oct. 17, 2012 and entitled“Systems and Methods for Signal Frequency Division in WirelessCommunication Systems,” now U.S. Pat. No. 9,008,162, which claimspriority to U.S. Provisional Patent Application Ser. No. 61/548,063,filed Oct. 17, 2011 and entitled “Combination of Main, Diversity andCross Polar Signals on One Coax Cable,” which are incorporated byreference herein.

BACKGROUND

1. Technical Field

The present invention(s) generally relate to combining signals across acable between units of a wireless communication system. Moreparticularly, the invention(s) relate to systems and methods for signalfrequency division in wireless communication systems.

2. Description of Related Art

In split mount microwave radio systems, a transceiver may include anindoor unit (IDU) and an outdoor unit (ODU) coupled to an antenna. Inone example, the IDU may be coupled to a server or other computer over awired network (e.g., LAN, WAN, or the Internet) or to a mobile networkbase station. Information to be wirelessly transmitted may be preparedby both the IDU and the ODU before wireless transmission. Similarly, theODU may receive signals from the antenna to provide to the server, othercomputer, or mobile network node via the IDU.

When multiple transmit signals are to be transmitted or multiple receivesignals are to be received, two different ODUs may be used. Eachdifferent ODU may be coupled to one or more IDUs with at least twocables to provide the signals. Unfortunately, multiple cables betweenone or more ODUs and one or more IDUs may increase cost and requireadditional parts.

SUMMARY

A system may include at least one antenna for receiving a first receivesignal having a first signal diversity property and a second receivesignal having a second signal diversity property. A first signal pathmay include a first frequency converter for downconverting the firstreceive signal to a first intermediate frequency signal having a firstintermediate frequency. A second signal path may include a secondfrequency converter for downconverting the second receive signal to asecond intermediate frequency signal having a second intermediatefrequency. A transducer module may route the first receive signal to thefirst signal path, and route the second receive signal to the secondsignal path. A first N-plexer may select the first intermediatefrequency signal or the second intermediate frequency signal fortransmission to a cable, and to provide a data signal based on aselected intermediate frequency signal to the cable.

In some embodiments, the first signal diversity property comprises afirst spatial property, and the second signal diversity propertycomprises a second spatial property, the second spatial property beingspatially diverse from the first spatial property. In variousembodiments, the first signal diversity property comprises a firstpolarization, and the second signal diversity property comprises asecond polarization, the second polarization being orthogonal to thefirst polarization. The transducer module may be configured todepolarize the first receive signal and the second receive signal.

In some embodiments, the system is incorporated into an Outdoor Unit(ODU) of a split-mount radio system.

The system may further comprise a second N-plexer may be configured toreceive the data signal from the cable, to provide the data signal to athird signal path if the selected intermediate signal is the firstintermediate frequency signal, and to provide the data signal to afourth signal path if the selected intermediate signal is the secondintermediate frequency signal. A modem may be configured to demodulatethe data signal and provide a demodulated data signal. A third frequencyconverter may be configured to downconvert the demodulated data signalto a baseband signal.

In various embodiments, the second N-plexer, the modem, and the thirdfrequency converter are within an Indoor Unit (IDU) of a split-mountradio. The third frequency converter may be configured to provide thebaseband signal to Customer Premises Equipment (CPE).

A system may include a first N-plexer configured to be coupled to acable, the first N-plexer configured to receive from the cable a firstdata signal and a second data signal, and to convert the first datasignal to a first intermediate frequency signal, and to convert thesecond data signal to a second intermediate frequency signal. A firstsignal path may include a first frequency converter configured toupconvert the first intermediate frequency signal to a first transmitsignal having a transmit frequency. A second signal path may include asecond frequency converter configured to upconvert the secondintermediate frequency signal to a second transmit signal having thetransmit frequency. A transducer module may be configured to process thefirst transmit signal and the second transmit signal. At least oneantenna may be configured to transmit the first transmit signal using afirst signal diversity property, and to transmit the second transmitsignal using a second signal diversity property.

In some embodiments, the first signal diversity property comprises afirst spatial property, and the second signal diversity propertycomprises a second spatial property, the second spatial property beingspatially diverse from the first spatial property. In variousembodiments, the first signal diversity property comprises a firstpolarization, and the second signal diversity property comprises asecond polarization, the second polarization being orthogonal to thefirst polarization. The transducer module may be configured to polarizethe first transmit signal and the second transmit signal.

In some embodiments, the system is incorporated into an Outdoor Unit(ODU) of a split-mount radio system.

A method may include: receiving a first receive signal having a firstsignal diversity property; receiving a second receive signal having asecond signal diversity property; downconverting, in a first signalpath, the first receive signal to a first intermediate frequency signalhaving a first intermediate frequency; downconverting, in a secondsignal path, the second receive signal to a second intermediatefrequency signal having a second intermediate frequency; routing thefirst receive signal to the first signal path; routing the secondreceive signal to the second signal path; selecting the firstintermediate frequency signal or the second intermediate frequencysignal for transmission to a cable; and providing a data signal based ona selected intermediate frequency signal to the cable.

In some embodiments, the first signal diversity property comprises afirst spatial property, and the second signal diversity propertycomprises a second spatial property, the second spatial property beingspatially diverse from the first spatial property. In variousembodiments, the first signal diversity property comprises a firstpolarization, and the second signal diversity property comprises asecond polarization, the second polarization being orthogonal to thefirst polarization. The method may further include depolarizing thefirst receive signal; and depolarizing the second receive signal.

The method may include: providing the first intermediate frequencysignal to a third signal path; providing the second intermediatefrequency signal to a fourth signal path; demodulating the firstintermediate frequency signal and the second intermediate frequencysignal to provide a demodulated intermediate frequency signal; anddownconverting the demodulated intermediate frequency signal to abaseband signal.

The method may further include providing the baseband signal to CustomerPremises Equipment (CPE).

A method may include receiving from a cable a first data signal;receiving from the cable a second data signal; converting the first datasignal to a first intermediate frequency signal having a firstintermediate frequency; converting the second data signal to a secondintermediate frequency signal having a second intermediate frequency;upconverting, in a first signal path, the first intermediate frequencysignal to a first transmit signal having a transmit frequency;upconverting, in a second signal path, the second intermediate frequencysignal to a second transmit signal having the transmit frequency; usinga first transducer module coupled to the first signal path and thesecond signal path to process the first transmit signal; using the firsttransducer to process the second transmit signal; using at least oneantenna to transmit the first transmit signal using a first signaldiversity property; and using the at least one antenna to transmit thesecond transmit signal using a second signal diversity property.

In some embodiments, the first signal diversity property comprises afirst spatial property, and the second signal diversity propertycomprises a second spatial property, the second spatial property beingspatially diverse from the first spatial property. In variousembodiments, the first signal diversity property comprises a firstpolarization, and the second signal diversity property comprises asecond polarization, the second polarization being orthogonal to thefirst polarization.

The method may further include polarizing the first transmit signal; andpolarizing the second transmit signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings are provided for purposes of illustration only and merelydepict typical or example embodiments. These drawings are provided tofacilitate the reader's understanding and shall not be consideredlimiting of the breadth, scope, or applicability various embodiments.

FIG. 1 is an environment including two transceiver units in someembodiments.

FIG. 2 is a block diagram regarding communication between twotransceiver units in a communication system that utilizes orthogonaltransmit and receive signals in some embodiments.

FIG. 3 depicts an exemplary embodiment of a wireless communicationsystem to transmit and receive orthogonally polarized system between anODU and an IDU (not depicted) over a coaxial cable in some embodiments.

FIG. 4 depicts a different exemplary embodiment of a wirelesscommunication system to transmit and receive orthogonally polarizedsignals between receivers/transmitters and a modem in some embodiments.

FIG. 5 is block diagram of another ODU in a communication system thatutilizes antenna spatial diversity in some embodiments.

FIG. 6 is block diagram of an IDU that communicates with an ODU over asingle cable in some embodiments.

FIG. 7 is a flow diagram for processing two or more receive signals overa split mount system utilizing a single cable in some embodiments.

FIG. 8 is a flow diagram for transmitting two diversity transmit signalsover a split mount system utilizing a single cable in some embodiments.

The figures are not intended to be exhaustive or to limit theembodiments to the precise form disclosed. It should be understood thatvarious embodiments may be practiced with modification and alteration.

DETAILED DESCRIPTION OF THE INVENTION

Some embodiments described herein enable a reduction of signalinterconnections between units in wireless communication systems such asmicrowave systems. In one example, the interconnection may be reduced byone or more cables.

In various embodiments, multiple transmit and/or receive signals may becombined on a single IDU-ODU cable (e.g., a coaxial cable). This processmay allow the transmit and receive signals to be dedicated to main anddiversity signals in one application and transmit and receive dualpolarization signals in another application. In one exemplaryimplementation of both these applications, the units at each end mayinclude a single modem card and a single ODU.

Various embodiments may allow flexibility to have a single modem, cable,and ODU ensemble for diversity combining in the modem from a set ofsignals carried on one cable. Mode switching in the modem and ODU mayallow transport dual polar signals in the transmit and receive directionon one cable. Exemplary processes may also support transmit MIMO on onecable. In one example, the signals are separated in frequency and mayuse 126 MHz and 500 MHz for receive signals, and 311 MHz and 700 MHz fortransmit signals. This arrangement may be capable of carrying 2 Gbs onone cable connected to one modem and ODU.

FIG. 1 is an environment 100 including two transceiver units 102 and 104in some embodiments. Each of the transceiver units 102 and 104 are splitmount radios. A split-mount radio has a part of the electronics mountedoutdoors with an antenna and part indoors. The outdoor unit (ODU) may bethe RF transmitter/receiver. In various embodiments, the indoor unit(IDU) contains a data access card (DAC) and a radio access card (RAC).The IDU may contain the modulator/demodulator, multiplexer, control, andtraffic interface elements. The IDU and ODU may be coupled togetherusing a cable or any other means.

By comparison, an all-indoor radio has all radio equipment installedinside and is connected to its antenna using a waveguide or coax feeder.A split-mount radio may be a point-to-point radio installation forlicensed 5 to 42+GHz frequency bands with the ODU direct-mounted to therear of the antenna to provide an integral antenna feed. By having theODU mounted with the antenna, split-mount may eliminate or reduce feederlosses, minimize or reduce rack occupancy, and/or lower installed costscompared to indoor radios.

For example, transceiver unit 102 may comprise an IDU 108 incommunication with a processor and/or a digital device, an ODU 110 incommunication with the IDU 108 over cables 118, a waveguide 112 incommunication with the ODU 110, and an antenna 116. The IDU 108 maycomprise a modulator/demodulator and control circuitry for providingdata from a digital device or a processor over line 114 to the antenna116 via the ODU 110 and/or the waveguide 112. Similarly, the IDU 108 mayalso be configured to receive information from the antenna 116 via theODU 110 for providing to the digital device or processor via the line114. The ODU 110 may comprise an RF transmitter/receiver and be coupledwith the antenna 116. The waveguide 112 may or may not be a part of theODU 110.

The IDU 108 of the transceiver unit 102 may be coupled to the ODU 110utilizing a coaxial cable 118. Although only one coaxial cable 118 isdepicted in FIG. 1, any number of coaxial cables may provide signalsbetween the IDU 108 and the ODU 110. Further, those skilled in the artwill appreciate that any number and/or type of cables may be configuredto receive and transmit signals between the IDU 108 and the ODU 110.

Similarly, transceiver unit 104 may comprise an IDU 120 in communicationwith a processor and/or a digital device, an ODU 122 in communicationwith the IDU 120 over cable 130, a waveguide 124 in communication withthe ODU 122, and an antenna 128. The IDU 120 may comprise amodulator/demodulator and control circuitry for providing data from adigital device or a processor over line 126 to the antenna 128 via theODU 122 and/or the waveguide 124. Similarly, the IDU 120 may also beconfigured to receive information from the antenna 128 via the ODU 122for providing to the digital device or processor via the line 126. TheODU 122 may comprise an RF transmitter/receiver and be coupled with theantenna 128. The waveguide 124 may or may not be a part of the ODU 122.

The IDU 120 of the transceiver unit 104 may be coupled to the ODU 122utilizing a coaxial cable 130. Although only one coaxial cable 130 isdepicted in FIG. 1, any number of coaxial cables may provide signalsbetween the IDU 108 and the ODU 110. Further, those skilled in the artwill appreciate that any number and/or type of cables may be configuredto receive and transmit signals between the IDU 108 and the ODU 110.

Those skilled in the art will appreciate that the transceiver unit 104may perform in a manner similar to the transceiver 102. In variousembodiments, the two transceiver units 102 and 104 may be incommunication with each other over a wireless communication tower 106.Those skilled in the art will appreciate that the transceiver units 102and 104, individually or together, may communicate with any digitaldevice or receiver.

The wireless communication tower 106 (e.g., cell tower or othermicrowave radio device) may be any device configured to receive and/ortransmit wireless information.

Various embodiments may comprise a wireless communication systemconfigured to transmit and receive orthogonally polarized signals orwireless communication systems with antenna spatial diversity. Multiplesignals (e.g., multiple transmit and/or multiple receive signals) may beshared between an ODU and an IDU over a single cable utilizing systemsand methods described herein. In some embodiments, multiple signals maybe shared between an ODU and a modem over a single cable.

In some embodiments, wireless communication systems may utilizepolarization diversity on a wireless channel to increase capacity orcompensate for fading conditions. Some systems, for example, utilize ahorizontally polarized signal and a vertically polarized signal on thesame wireless channel to either increase capacity of communication orredundantly communicate data between communications sites when the samewireless channel is experiencing a fading condition. In a polarizationdiversity system, there may be two transmit signals (e.g., one transmitsignal to be transmitted horizontally and one transmit signal to betransmitted vertically) as well as two receive signals (e.g., onereceive signal received by the antenna as a horizontally polarizedsignal and one receive signal received by the same antenna as avertically polarized signal).

Other wireless systems may utilize antenna spatial division. In thesesystems, multiple antennas may be utilized to provide redundancy in caseof fading signal conditions. In one example, a main antenna may beutilized to receive a main signal and a diversity antenna may beutilized to receive a diversity signal. The diversity signal may berequired if the main signal is faded or otherwise contains errors. Inthese systems, for example, multiple receive signals may be received(e.g., a main signal by the first antenna and a diversity signal by thesecond antenna) but only a single transmit signal may be transmitted.

In order to communicate multiple receive and/or transmit signals fromthe ODU to the modem, multiple coaxial cables may be used. In someembodiments, however, a single coaxial cable may be utilized inconjunction with a system of frequency division to maintain the receiveand/or transmit signals between the ODU and IDU (or modem). Thoseskilled in the art will appreciate that any technique may be used tomaintain or retain the signals across the single cable.

FIG. 2 depicts a microwave communication system that is configured totransmit and receive orthogonal systems utilizing multiple cables (i.e.,without utilizing frequency division to transmit signals across thecables). In the system as depicted in FIG. 2, the orthogonal transducermodule 202 is external to the two outdoor-unit/radio frequency units 204and 206. Both outdoor-unit/radio frequency units 204 and 206 areseparately coupled to the indoor unit/signal processing unit via acoaxial cable. Some embodiments described herein allow for communicationbetween one or more outdoor-unit/radio frequency units with one or moreindoor unit/signal processing units over a single cable by allowingfrequency division of different receive and/or transmit signals.

At a high level, FIG. 2 is a block diagram regarding communicationbetween two transceiver units in a communication system that utilizesorthogonal transmit and receive signals in some embodiments. FIG. 2comprises two outdoor-unit (ODU)/radio frequency unit (RFU) 204 and 206coupled to an orthomode transducer (OMT) 202. The OMT 202 is coupled toone or more antennas (not depicted). The ODU/RFU 204 comprises atransceiver module 210 configured to process signals that have been orwill be vertically polarized (e.g., received signals that werevertically polarized and signals that are to be transmitted in avertical polarization). Similarly, the ODU/RFU 206 comprises atransceiver module 212 configured to process signals that have been orwill be horizontally polarized (e.g., received signals that werehorizontally polarized and signals that are to be horizontally in avertical polarization).

The OMT 202 is configured to route polarized signals to different signalpaths based on polarization. In some embodiments, the OMT 202 isconfigured to polarize and depolarize signals. The OMT 202 may comprisean orthomode transducer and/or waveguide filters.

In one example, when a communications site is transmitting data, the OMT202 receives modulated carrier signals from its respective transceivermodules 210 and 212, polarizes the modulated carrier signals accordingto the port designations (i.e., vertical polarization, and horizontalpolarization), and provides the resulting polarized signals through theantenna. Conversely, when the communications site is receiving data, theOMT 202 receives polarized-diverse signals from the antenna and maydepolarize the polarized-diverse signals, which may result in amodulated carrier signal for each polarized-diverse signal. Thesemodulated carrier signals may be subsequently provided to transceivermodules 210 and 212 via ports that correspond to differentpolarized-diverse signals (e.g., the modulated carrier signal from thevertically polarized signal is provided to the transceiver 132 coupledto the vertical polarization port). In various embodiments, waveguidefilters may both direct and convert the signals as necessary.

Each of the transceiver modules 210 and 212 is coupled to the IDU/SPU208 via connections 224 and 226 which allows the transceivers to sendand receive first and second data streams. Each of the transceivermodules 210 and 212 is also coupled to the OMT 202 through waveguideports (e.g., rectangular waveguide ports). In some embodiments, theseconnections allow the transceivers 210 and 212 to send non-polarizedcarrier signals to, and receive depolarized carrier signals from, theOMT 202.

The transceiver modules 210 and 212 (and/or the signal processing module218) may also modulate the data stream onto the carrier signal using avariety of data modulation schemes including, but not limited to,quadrature-amplitude modulation (QAM), phase-shift keying (PSK),frequency-shift keying (FSK), trellis coded modulation (TCM), andvariations thereof.

Additionally, for some embodiments, the transceiver modules 210 and 212(and/or the signal processing module 218) may further implement adaptivemodulation schemes configured to adjust the data modulation of the datastream onto the carrier signals based on the conditions of the wirelesschannel. For example, when the wireless channel conditions between twocommunications sites change such that they adversely affect thevertically polarized signal traveling over the wireless channel but notthe horizontally polarized signal, the transmitting communications sitemay adjust the data modulation of the carrier signal for the verticallypolarized signal from 256 QAM to 16 QAM. This change may be applieduniformly to the horizontally polarized signal as well, or may beisolated to just the vertically polarized signal. In some embodiments,the modulation change implemented by the adaptive modulation may beuniform across all carrier signals provided by the signal quality module108, and not just isolated to the polarization-diverse signal that isadversely affected by the wireless channel conditions. Additionally, invarious embodiments, the determination or activation of an alternativemodulation at the transmitting communications site 102 may be determinedremotely by the receiving communications site 120, which then instructsthe transmitting communications site 102 of its determination.

The OMT 202 is coupled to an antenna via a connection (e.g., circularwaveguide port) which allows the OMT 202 to transmit and receivepolarized wireless signals using the antenna.

The IDU/SPU 208 comprises a signal quality module 214, a controllermodule 216, a signal processing module 218, and a data interface module220. The signal quality module 214 is configured to combine and splitdata streams. For example, the signal quality module 214 may beconfigured to split data streams onto cables 224 and 226. Similarly, thesignal quality module 214 may be configured to combine data streams fromcables 224 and 226 and provide the combined data streams to the signalprocessing module 218.

Those skilled in the art will appreciate that a modem may comprise allor part of the signal quality module 214 and the signal processingmodule 218.

The signal processing module 218 is coupled to the data interface module220 and the signal quality module 214. According to some embodiments,when the communications system is transmitting, the signal processingmodule 218 may be configured to convert data received from the datainterface module 220 to a processed data stream, which is then providedto the signal quality module 214. When the communications system isreceiving, the signal processing module 218 may be configured to converta processed data stream received from the signal quality module 214 to aform that may be received and further processed by customer equipment.

The signal processing module 218 may be configured to process data for anumber of purposes including, for example, conversion of data (e.g.,converting between data and I-Q data), data compression, errorcorrection, processing to further reduce of correlation between thepolarization-diverse signals, filtering, and measuring data signals. Forexample, by processing the data stream received from the signal qualitymodule 214, the signal processing module 218 may measure, or assist inthe measurement, of the overall strength of a signal stream received bythe antenna. Additionally, based on wireless channel conditions, thesignal processing module 218 may be utilized to determine whether apower adjustment is warranted for one or more of thepolarization-diverse signals being transmitted (e.g., increase power ofthe vertically or horizontally polarized signal), determine whether moredata should be diverted to one polarization-diverse signal over another,determine whether one of the polarization-diverse signals should bedisabled, or assist in adaptive modulation process (e.g., assist todetermine the best modulation for one or both transceiver modules).

Measurement of signal strength may be used to determine whether areceived signal meets a minimum receive signal level threshold. Fromthis determination, a receiving communications site may determinewhether the wireless channel on which a signal is received isexperiencing a fading condition, and may inform the transmittingcommunications site accordingly. To address the fading condition, thetransmitting communications site may transmit data such thatpolarization-diverse signals carry redundant data, thereby increasingthe likelihood that data transmitted is successfully received by thereceiving communications site. Depending on the embodiment, thetransmitting communications site may transmit data redundantly wheninstructed to do so by the receiving communications site, or based onthe transmitting communications site's own determination.

For some embodiments, information regarding wireless channel conditionsis shared between the communications sites. In addition to sharing themeasured strength of the signal received (e.g., as a received signalstrength indicator [RSSI]), communications sites may gather and shareother information regarding observed conditions, such as signal-to-noise(SNR) ratio over the wireless channel and telemetry data).

The signal quality module 214 is coupled to the signal processing module218 and a controller module 216. The controller module 216 may beconfigured to control operation of the signal quality module 214 (e.g.,how to split or combine data streams). In some embodiments, the signalquality module 214 may be configured to split a data stream receivedfrom the signal processing module 218 into two data streams, which arethen sent to the ODU/RFU 204 or 206 via connections 224 and 226,respectively. In various embodiments, the signal quality module 214 maybe configured to combine a two data streams received from an ODU/RFU 204and 206, via connections 224 and 226, respectively, into one datastream, and provide the one data stream to the signal processing module218 for processing.

Those of ordinary skill in the art would appreciate that in someembodiments, the signal quality module 214 may be replaced by a routermodule that routes signals to a passive splitter module and a passivecombiner module. For example, in some embodiments, the passive combinermodule may comprise a passive concatenator, and a passive redundancycomparator.

For some embodiments, when the wireless channel being utilized is nolonger experiencing a fading condition, the transmitting communicationssite may configure itself to divide the original data stream into two ormore data streams such that each of the data streams contains adifferent portion of the original data stream, and to transmit those twoor more streams using the polarization-diverse signals such that eachpolarization-diverse signal carries different data. In order to receivethe data, the receiving communications site may configure itselfaccordingly to combine the data streams extracted from receivedpolarization-diverse signals, and create a single data stream.

For instance, the signal quality module 214 for the transmittingcommunications site may be instructed (by its respective control module216) to split a first data stream and a second data stream from theoriginal data stream, each of the first and second data streamscontaining mutually exclusive portions of data from the original datastream. Subsequently, each of the first and second data streams may beprovided by the signal quality module 108 to the pair of transceivermodules 210 and 212—one data stream going to a transceiver (vertical)module 210, and the other data stream going to a transceiver(horizontal) module 212. Depending on the embodiment, the splittingprocess may divide the original data stream based on a number ofcriteria including, for example, data type, data block size, andpriority of data.

In some embodiments, the receiving communications site may configureitself to receive different data on each of the polarization-diversesignals. For example, the signal quality module 214 may be instructed toconcatenate portions of a first data stream received with portions of asecond data stream received in order to create a single data streamcomprising data from the transmitting communications site.

One of ordinary skill in the art would readily understand that wheresome embodiments implement point-to-point wireless communications (e.g.,microwave/millimeter frequency communications system), bi-directionaldata transfer between two communications site may be facilitated usingtwo or more separate wireless channels between the sites. Each wirelesschannel may have a different center frequency and carrying its own setof polarization-diverse signals.

As used herein, the term set may refer to any collection of elements,whether finite or infinite. The term subset may refer to any collectionof elements, wherein the elements are taken from a parent set; a subsetmay be the entire parent set.

As used herein, the term module might describe a given unit offunctionality that can be performed in accordance with one or moreembodiments. As used herein, a module might be implemented utilizing anyform of hardware, software, or a combination thereof. For example, oneor more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs,logical components, software routines or other mechanisms might beimplemented to make up a module. In implementation, the various modulesdescribed herein might be implemented as discrete modules or thefunctions and features described can be shared in part or in total amongone or more modules. Even though various features or elements offunctionality may be individually described or claimed as separatemodules, one of ordinary skill in the art will understand that thesefeatures and functionality can be shared among one or more commonsoftware and hardware elements, and such description shall not requireor imply that separate hardware or software components are used toimplement such features or functionality.

Where components or modules of some embodiments are implemented in wholeor in part using software, in some embodiments, these software elementscan be implemented to operate with a digital device capable of carryingout the functionality described with respect thereto.

FIG. 3 depicts an exemplary embodiment of a wireless communicationsystem to transmit and receive orthogonally polarized system between anODU 300 and an IDU (not depicted) over a coaxial cable 324 in someembodiments. In particular, FIG. 3 depicts an ODU 300 that providesmultiple receive signals and receives multiple transmit signals over asingle coaxial cable 324 to an IDU or modem.

The ODU 300 comprises a circular waveguide 304, an orthomode transducer(OMT) 306, waveguide filters 308 and 312, radio frequency(RF)—intermediate frequency (IF) converters 314 and 316, and N-plexer322. The OMT 306 is coupled to the antenna 302 via the circularwaveguide 304. The OMT 306 is also coupled to waveguide filters 308 and312 via signal paths. The waveguide filters 308 and 312 are electricallycoupled to RF-IF converter(s) 314, and 316, respectively. The N-plexer322 is electrically coupled to the RF-IF converter(s) 314 and 316 viasignal paths 318 and 320. The N-plexer 322 is further electricallycoupled to the IDU (not depicted) via the coaxial cable 324.

The antenna 302 may be any antenna used for communication. For example,the antenna 302 may be a parabolic antenna or any type of antenna. Theantenna 302 may be part of a microwave communication system. In someembodiments, the antenna 302 is configured to receive polarizedcommunication systems. There may be any number of antennas including,for example, different antennas for receiving differently polarizedsignals. For the purposes of this discussion, polarized signals isreferred to as including horizontally polarized and verticallypolarized. Those skilled in the art will appreciate that any orthogonalsignals may be utilized.

The antenna 302 may be coupled with the OMT 306 via a circular waveguide302. In some embodiments, the circular waveguide 302 is part of aresizable collar that may be mounted to or on the antenna 302. Thewaveguide 302 may be any waveguide kind or type of waveguide. Forexample, the waveguide 302 may be hollow or dielectric. In someembodiments, the waveguide 302 comprises a waveguide of any shape.

The OMT 306 is an orthomode transducer that may be coupled and/orinclude the circular waveguide 304. The OMT 306 may be or include amicrowave circulator. In one example, the OMT 306 is or includes apolarization duplexer. In various embodiments, the OMT 306 directspolarized signals. For example, the OMT 306 may receive a horizontallypolarized receive signal and a vertically polarized receive signal fromthe antenna 302. The OMT 306 may direct the horizontally polarizedreceive signal to the waveguide filters 308 and direct the verticallypolarized receive signals to the waveguide filters 312.

In some embodiments, the OMT 306 is contained within the ODU 300. Bycoupling the OMT 306 and/or the waveguide filters 308 and/or 312 withinthe same ODU 300 (e.g., within the same enclosure), ports and/or cablingbetween the components may be reduced thereby saving cost and reducingthe parts necessary to install and maintain the system. In one example,the OMT 306 may be directly coupled to the waveguide filters 308 and 312via a waveguide. The waveguide filters 308 and 312 may be electricallycoupled (e.g., via signal paths) with RF-IF converter(s) 314 and 316,respectively.

Those skilled in the art will appreciate that, in some embodiments, theOMT 306 is not a part of the ODU 300 (e.g., the OMT 306 is outside ofthe ODU 300). The OMT 306 may be coupled to the ODU 300 in any number ofways. In one example, the circular waveguide 304, the OMT 306, and thewaveguide filters 308 and 312 may be outside the ODU 300. The ODU 300may be coupled to the external waveguide filters 308 and 312 in anynumber of ways including, for example, over a coaxial cable.

Although FIG. 3 may appear to depict a signal path between the waveguidefilters 308 and 312 and the OMT 306, those skilled in the art willappreciate that the waveguide filters 308 and 312 may be coupleddirectly to the OMT 306 (e.g., via two or more rectangular waveguides).

Waveguide filters 308 and 312 may each be configured to filter anddirect transmit and receive signals. The waveguide filters 308 and 312may prevent receive signals from propagating back towards the antenna302. Similarly, the waveguide filters 308 and 312 may prevent transmitsignals from propagating back towards the transmitters or components ofthe transmitters (e.g., RF-IF converter(s) 314 and 316, respectively).

Each waveguide filter 308 and/or 312 may comprise a transmit filter anda receive filter. The transmit filter may be configured to receivesignals from a transmitter and provide the signals to the antenna 302via a stacked waveguide circulator component or OMT 306 (which mayprovide the signal to the antenna 302 via the circular waveguide 304).In one example, if a signal is provided through the transmit filter tothe transmitter (e.g., a signal is provided from the antenna 302), thetransmit filter may block the signal. Subsequently the signal may bereturned or reflected back to a stacked waveguide circular or OMT 306which may redirect the signal to the next port (e.g., the receivefilter). The transmit filter is a filter that may reduce or eliminateundesired aspects (e.g., noise) of a signal to be transmitted from atransmitter to the antenna.

The receive filter may be configured to receive signals from an antenna302 (via the stacked waveguide circulator component or OMT 306) andprovide the signals to a receiver (which may comprise the RF-IFconverter 314 or 316). In one example, if a receive signal is providedback towards the antenna 302, the receive filter may block the signal.Subsequently the signal may be returned or reflected to the RF-IFconverter 314 or 316. The receive filter, like the transmit filter, mayreduce or eliminate undesired aspects (e.g., noise) of a received signalfrom the antenna. The transmit filter and the receiver filter may bestacked and/or coupled.

In some embodiments, an SMA isolator is a SubMinitature version A (SMA)coaxial RF connector coupled between a waveguide filter and atransmitter or receiver. In one example, the SMA isolator may transmitmicrowave or radio frequency power in one direction. The SMA isolatormay shield equipment. The SMA isolator may be coupled to the transmitfilter and a transmitter. In another example, the SMA isolator iscoupled to the receiver filter and a receiver.

In some embodiments, the SMA isolator prevents signals from beingprovided through the transmit filter back to the transmitter. If asignal is provided through the transmit filter to the transmitter, theSMA isolator may block the signal. Subsequently the signal may bereturned or reflected back to the stacked waveguide circular or OMT 306which may redirect the signal to the receive filter.

Although only an OMT 306, waveguide filters 308 and 312, RF-IFconverter(s) 314 and 316, and N-plexer 322 are depicted as beingcontained within the ODU 300, those skilled in the art will appreciatethat the ODU 300 may comprise any devices, circuits or components. Forexample, the RF-IF converter(s) may be a part of a transmitter,receiver, or both. In some embodiments, a transmitter may comprisepredistorter modules configured to add predistortion to cancel orinterfere with nonlinear artifacts generated by a power amplifier or thelike. Similarly, the transmitter and/or receiver may comprise gainadjusters, phase adjusters, and/or filters for example.

The RF-IF converter 314 and 316 are any converters configure toupconvert or downconvert signals. In various embodiments, the RF-IFconverters 314 comprise two different converters. For example, one ofthe RF-IF converters 314 may be configured to downconvert an RF transmitsignal from the antenna 302 to IF. This RF-IF converter 314 may beconsidered as part of a transmitter. Another one of the RF-IF converters314 may be configured to upconvert an IF receive signal from theN-plexer 322 to RF. This other RF-IF converter 314 may be considered aspart of a receiver.

Those skilled in the art will appreciate that although FIG. 3 depictsRF-IF converter(s) 314 and 316, there may be receivers and transmittersor components associated with transmitting or receiving between theN-plexer 322 and the waveguide filters 308. For example, a first RF-IFconverter 314 may be on a first signal path between the N-plexer 322 andthe waveguide filters 308. A second RF-IF converter 314 may be on asecond signal path between the N-plexer 322 and the waveguide filters308. Similarly, two different RF-IF converters 316 may be on third andfourth signal paths, respectively, between the N-plexer 322 and thewaveguide filters 308.

In various embodiments, a first RF-IF converter 314 is configured toconvert a receive signal from the RF frequency to an intermediatefrequency. A first RF-IF converter 316 may also be configured to converta different receive signal from the RF frequency to a differentintermediate frequency for frequency division. For example, the RF-IFconverter 314 may convert the RF receive signal (received as ahorizontally polarized signal by the antenna 302) to 126 MHz while theRF-IF converter 316 may convert a different RF receive signal (receivedas a vertically polarized signal by the antenna 302) to 500 MHz. Thoseskilled in the art will appreciate that the RF-IF converters 314 and 316(or one or more other components of the ODU 300) may convert the twodifferent receive signals to different frequencies to allow forfrequency division and transmission over the coaxial cable 324.

Similarly, in various embodiments, a second RF-IF converter 314 isconfigured to convert a transmit signal from the IF frequency to an RFfrequency. A second RF-IF converter 316 may also be configured toconvert a different transmit signal from a different IF frequency to theRF frequency. In order to maintain two or more transmit signals over thecoaxial cable, the transmit signals may have different frequencies. Forexample, the transmit signal received by the RF-IF converter 314 viasignal path 318 may be 311 MHz while the transmit signal received by theRF-IF converter 316 via signal path 320 may be 700 MHz. Those skilled inthe art will appreciate that the transmit signals may be at anyfrequency.

In some embodiments, the RF-IF converter 314 and RF-IF converter 316 maynot convert a signal from RF to IF or from IF to RF, rather, theconverters may convert a signal from RF to any frequency (e.g.,baseband) and convert any frequency to RF.

The N-plexer 322 is a multi-band device that may be configured to director route multiple signals at different frequencies. For example, theN-plexer 322 may receive a receive signal at 126 MHz from RF-IFconverter(s) 314 and a receive signal at 316 MHz from RF-IF converter(s)316. The N-plexer 322 may direct both receive signals over the singlecable 324.

The N-plexer 322 may also receive multiple transmit signals at differentfrequencies and route the transmit signals. For example, the N-plexer322 may receive a transmit signal at 311 MHz and route the transmitsignal to path 318. Similarly, the N-plexer 322 may receive a transmitsignal at 700 MHz and route the transmit signal to path 320. TheN-plexer 322 may route a plurality of signals based on frequencies ofthe signals.

Although signal path 318 is depicted as a signal path, those skilled inthe art will appreciate that the signal path 318 may be multiple paths(e.g., the signal path 318 may comprise two separate signal pathselectrically coupled to different converters of the RF-IF converters314, respectively). Similarly, although signal path 320 is depicted as asingle path, the signal path 320 may also be multiple paths (e.g., thesignal path 320 may comprise two separate signal paths electricallycoupled to different converters of the RF-IF converters 316,respectively). Multiple signal paths coupled to the N-plexer 322 arefurther discussed with regard to FIG. 4.

Although an N-plexer 322 is depicted in FIG. 3, those skilled in the artwill appreciate that any device, circuit(s), and/or component(s) may beconfigured to maintain and/or propagate multiple signals across cable324 without interfering the signals or the signals interfering with eachother.

The coaxial cable 324 couples the ODU 300 and a modem or the IDU (notdepicted in FIG. 3. The coaxial cable 324 is not limited to coax but maybe any cable or combination of cables.

FIG. 4 depicts a different exemplary embodiment of a wirelesscommunication system to transmit and receive orthogonally polarizedsignals between receivers/transmitters and a modem in some embodiments.FIG. 4 depicts an ODU 400 which is coupled to an antenna 402 and a cable432. Although FIG. 4 depicts an ODU 400 or an enclosure housing similarequipment to an ODU, those skilled in the art will appreciate that theODU 400 may be include one or more units. Further, the components of theODU 400 may be housed in different enclosures. In some embodiments, oneor more of the components of the ODU 400 may not be enclosed.

Similar to ODU 300, the ODU 400 comprises a circular waveguide 404, anorthomode transducer (OMT) 406, and waveguide filters 408 and 412.Waveguide filters 408 may be coupled to transmitter 414 and receiver 416over separate signal paths. Similarly, the waveguide filters 412 may becoupled to transmitter 418 and receiver 420 over separate signal paths.

Transmitter 414 and receiver 416 may be electrically coupled to theN-plexer 430 via signal paths 422 and 424, respectively. Transmitter 418and receiver 420 may also be electrically coupled to the N-plexer 430via signal paths 426 and 428, respectively. The N-plexer 430 is furtherelectrically coupled to a modem or IDU (not depicted) via the cable 432.

The antenna 402 may be similar to the antenna 302. For example, theantenna 402 may be a parabolic antenna or any type of antenna that, inthis example, is configured to transmit and receive polarizedcommunication systems.

The antenna 402 may be coupled with the OMT 406 via a circular waveguide402. Like the OMT 306, the OMT 406 is an orthomode transducer that maybe coupled and/or include the circular waveguide 404. The OMT 406 may bea microwave circulator. In one example, the OMT 406 is a polarizationduplexer.

Waveguide filters 308 and 412, similar to waveguide filters 308 and 312,may each be configured to filter and direct transmit and receivesignals. The waveguide filters 408 and 412 may prevent receive signalsfrom propagating back towards the antenna 402. Similarly, the waveguidefilters 408 and 412 may prevent transmit signals from propagating backtowards the transmitters 414 and 418, respectively.

The transmitters 414 and 418 are any components configured to processand/or convert signals to an RF or any frequency to be transmitted bythe antenna 402. The transmitter 414 may receive a transmit signal at411 MHz from N-plexer 430 via signal path 422. The transmit signal mayultimately be transmitted by the antenna 402 as a horizontally polarizedsignal. The transmitter 414 may upconvert the received transmit signalto an RF frequency and provide the processed, upconverted transmitsignal to the waveguide filters 408. The transmitter 418 may receive atransmit signal at 700 MHz from N-plexer 430 via signal path 426. Thetransmit signal may ultimately be transmitted by the antenna 402 as avertically polarized signal. The transmitter 418 may upconvert thereceived transmit signal to an RF frequency and provide the processed,upconverted transmit signal to the waveguide filters 412.

The receivers 416 and 420 are any components configured to processand/or convert signals from an RF to an IF, baseband, or any frequencyto be provided to the modem (not depicted) via the cable 432. Thereceivers 416 and 420 may convert receive signals (e.g., horizontallypolarized signals and vertically polarized signals received by theantenna 402) from an RF frequency to different frequencies that willallow the N-plexer 430 to provide the converted receive signals over thecable 432.

The receiver 416 may receive a receive signal from the waveguide filters408 and convert the receive signal to 126 MHz which may be provided tothe N-plexer 430 via signal path 422. The receive signal may have beenreceived by the antenna 402 as a horizontally polarized signal.Similarly, the receiver 420 may receive a receive signal from thewaveguide filters 412 and convert the receive signal to 500 MHz whichmay be provided to the N-plexer 430 via signal path 428. The receivesignal may have been received by the antenna 402 as a verticallypolarized signal.

The N-plexer 430 may be similar to the N-plexer 322. The N-plexer 430 isa multi-band device that may be configured to direct or route multiplesignals at different frequencies. For example, the N-plexer 430 mayreceive a receive signal at 126 MHz from receiver 416 via signal path424 and receive a receive signal at 500 MHz from receiver 420 via signalpath 428. The N-plexer 430 may direct both receive signals over thesingle cable 432.

The N-plexer 430 may also receive multiple transmit signals at differentfrequencies and route the transmit signals. For example, the N-plexer430 may receive a transmit signal at 311 MHz from the single cable 432and route the transmit signal over signal path 422. Similarly, theN-plexer 430 may receive a transmit signal at 700 MHz and route thetransmit signal to path 426. The N-plexer 430 may route a plurality ofsignals based on frequencies of the signals.

FIG. 5 is block diagram of another ODU 510 in a communication systemthat utilizes antenna spatial diversity in some embodiments. The ODU 510may be in communication with main antenna 502 and diversity antenna 504.In various embodiments, two receive signals, including a main receivesignal and a diversity receive signal, may be received by the ODU 510.The diversity receive signal may be utilized to correct the main receivesignal if the main receive signal is weak or otherwise in error due to afading channel. In some embodiments, only the main antenna 502 isutilized for transmitting signals from the ODU 510. In this example, theODU 510 may provide a single transmit signal to the main antenna 502 andreceive two receive signals from the main antenna 502 and diversityantenna 504.

The ODU 510 may comprise circular waveguides 506 and 508 coupled towaveguide filters 512 and 514, respectively. The RF-IF Converter(s) 516and 518 may be electrically coupled to the waveguide filters 512 and514, respectively. The RF-IF Converter(s) 516 and 518 may be coupled tothe N-plexer 524 via signal paths 520 and 522, respectively. Thecircular waveguides 506 and 508, waveguide filters 512 and 514, RF-IFConverter(s) 516 and 518, and N-plexer 524 may be similar to thecircular waveguides, waveguide filters, RF-IF Converter(s) and N-plexerof FIGS. 3 and 4.

In various embodiments, the N-plexer 524 may receive a transmit signalfrom the cable 524 to provide to the main antenna 502 (e.g., via signalpath 520). The transmit signal may be at a different frequency than thefrequency of the receive signals or any other signal on the cable 524.For example, the frequency of the transmit signal may be 311 MHz whilethe receive signals may be 126 MHz and 500 MHz, respectively.

In various embodiments, the cable 524 may provide multiple receiveand/or transmit signals as well as power and/or telemetry. The N-plexer524 and another N-plexer (see FIG. 6) may be electrically coupled viathe cable 524. The N-plexers may provide signals to the cable 524 aswell as direct signals from the cable 524 to a particular signal pathbased on the frequency of the signal (e.g., each signal on the cable524, including but not limited to receive signals, transmit signals,power signals, and telemetry signals, may each have a unique frequencyto take advantage of frequency division).

Those skilled in the art will appreciate that power may be provided byany power module over the cable to the ODU 510 and/or one or morecomponents for the ODU 510. The power module may, for example, provideDC power to the ODU 510.

The telemetry signal may include data that is used to communicatebetween components of the IDU (e.g., modem) and the ODU 510. Forexample, in some split-mount embodiments, a radio frequency (RF) signal(e.g., microwave frequency signal) may be downconverted to an IFfrequency and subsequently received at the IDU (e.g., at a modem).Errors or signal corrections may be identified by one or more componentsof the IDU. An error detection module in the IDU may be transmitted backto the ODU 510 as telemetry data, which the ODU 510 translates intoadjustments which may, for example, be applied (e.g., the RF signal maybe demodulated, phase corrected based on the telemetry data, andremodulated within the ODU 510).

FIG. 6 is block diagram of an IDU 600 that communicates with an ODU overa single cable 432 in some embodiments. The IDU 600 may be any unitconfigured to communicate with the ODU 400 over the cable 432. AlthoughFIG. 6 identifies an IDU 600, those skilled in the art will appreciatethat systems and methods described herein may, in some embodiments, beutilized with an N-plexer and a modem that communicates with a separateunit over the cable 432.

The IDU 600 may comprise an N-plexer 602 electrically coupled with thecable 432 and a modem 608. The modem 608 may further be coupled with theoptional IF-BB converter 610 which may be in communication with customerpremises equipment. Those skilled in the art will appreciate that theIDU 600 may comprise any number of components, including, for example, apower module and a telemetry module. The power module may be configuredto provide power to the ODU 400 via the cable 432. The telemetry modulemay be configured to detect and correct for errors in received signalsand provide corrective information to the ODU 400 via the cable 432.Further, the IDU 600 may comprise gain adjusters, filters, and/or phaseadjusters, or the like.

In some embodiments, the components of the IDU 600 may be in any order.In some embodiments, the IF-BB converter 610 may be coupled to theN-plexer 602 and the modem 608. For example, the IF-BB converter 610 maybe configured to downconvert diversity receive signals received from theN-plexer 602 before providing the downconverted diversity receivesignals to the modem 608. Similarly, the IF-BB converter 610 mayupconvert diversity transmit signals to different frequencies. The IF-BBconverter 610 may receive the diversity transmit signals from the modem608 and provide the upconverted signals to the N-plexer 602.

In various embodiments, the N-plexer 602 may direct diversity receivesignals from the cable 432 to the signal path 604 or signal path 606based on the different frequencies of the two diversity receive signals.The N-plexer 602 may also receive transmit signals from the modem 608.The diversity transmit signals may each have different frequencies thaneach other and different frequencies than the diversity receive signals.In some embodiments, the N-plexer 602 receives the two transmit signalsvia two other signal paths (e.g., other than the signal paths 604 and606). For example, there may be four signal paths between the modem 608and the N-plexer 602. Each different signal path may be for a differentreceive or transmit signal. Those skilled in the art will appreciatethat there may be any number of signals and corresponding signal pathsbetween the modem 608 and the N-plexer 602.

The modem 608 may be any modem configured to demodulate diversityreceive signals and modulate diversity transmit signals (e.g.,upconverted signals to be transmitted received from the customerequipment). In various embodiments, the modem 608 converts the modulateddiversity transmit signals to different frequencies (e.g., 311 MHz and700 MHz, respectively).

The optional IF-BB converter 610 may be any converter configured toupconvert signals to be transmitted received from customer equipment(e.g., from a baseband to an IF frequency) and downconvert signalsreceived from the modem 608 (e.g., demodulated receive signals from IFfrequency to a baseband frequency). In various embodiments, the IF-BBconverter 610 converts the signals to be transmitted to differentfrequencies (e.g., 311 MHz and 700 MHz, respectively). Although theIF-BB converter 610 is identified as “IF-BB,” the IF-BB converter 610may upconvert signals to be transmitted to any frequency (not just IF)and the IF-BB converter 610 may downconvert signals to any frequency(not just baseband).

In some embodiments, the IF-BB converter 610 is optional. For example,the modem 608 may downconvert the diversity receive signals receivedfrom the N-plexer 602 and upconvert signals to be transmitted. Invarious embodiments, the modem 608 converts the signals to betransmitted to different frequencies (e.g., 311 MHz and 700 MHz,respectively).

In various embodiments, there may any number of signal paths between themodem 608 and the IF-BB converter 610 (if present). For example, theIF-BB converter 610 may provide upconverted transmit signals (which eachhave frequencies distinct from each other) to the modem 608 over twodifferent signal paths. The modem 608 may provide demodulated receivesignals to the IF-BB converter 610 over one or two other signal paths.

In various embodiments, the IDU 600 or second unit may include a powermodule configured to provide power to the ODU 400. For example, thepower module may provide a power signal to the N-plexer 602. TheN-plexer 602 may provide the power signal to the single cable 432. Sincethe power signal may be DC power, the frequency of the power signal isdifferent (e.g., 0 Hz) from that of other signals that may bepropagating on the cable 432. As a result, the N-plexer 430 of FIG. 4may receive the power signal from the cable and provide the power signalto the correct path to power the ODU 400.

Further, the IDU 600 or second unit may include a telemetry moduleconfigured to provide a telemetry signal to the ODU 400 to allow forcommunication between the two units. The telemetry signal may be at afrequency that is different than other signals propagating across thesingle cable 432. For example, the telemetry module may provide atelemetry signal to the N-plexer 602. The N-plexer 602 may provide thetelemetry signal to the single cable 432. Since the frequency of thetelemetry signal is different (e.g., 5 HMz) from that of other signalsthat may be propagating on the cable 432, the N-plexer 430 of FIG. 4 mayreceive the telemetry signal from the cable and provide the telemetrysignal to the correct path to allow for communication.

In various embodiments, the IDU 600 may comprise a signal qualitymodule, controller module 216, signal processing module 218, and/or adata interface module 220 as discussed in FIG. 2. In variousembodiments, the signal quality module 214 and/or the signal processingmodule 218 may apply a receive signal from a diversity antenna (in anantenna spatial diversity system) when errors are detected. In someembodiments, the receive signal from the diversity antenna may bedisregarded (e.g., when the quality of the receive signal from the mainantenna is high or above a threshold).

Although a single cable 432 is depicted in FIGS. 3-6, those skilled inthe art will appreciate that any number of cables may be utilized. Forexample, multiple signals at different frequencies may propagate throughany of the cables utilizing systems and methods described herein.

FIG. 7 is a flow diagram for processing two diversity receive signalsover a split mount system utilizing a single cable in some embodiments.In step 702, at least one antenna receives a first diversity receivesignal and a second diversity receive signal. In some embodiments, thefirst and second diversity receive signals have orthogonal polarizationsand may be received by a single antenna.

Although polarization systems are discussed regarding FIG. 7, varioussystems and methods described herein may apply to main and diversityreceive signals received by two spatially diverse antennas,respectively. Those skilled in the art will appreciate that any numberof diversity receive signals may be received over any number ofantennas.

In step 704, an OMT 406 within an ODU 400 may receive orthogonallypolarized first and second diversity receive signals from the antenna402 via a circular waveguide 404 and provide the first diversity receivesignal to waveguide filters 408 via a first path (e.g., rectangularwaveguide coupling the OMT 406 to the waveguide filters 408). In step706, the OMT 406 may provide the second diversity receive signal towaveguide filters 412 via a second path (e.g., a different rectangularwaveguide coupling the OMT 406 to the waveguide filters 412). In variousembodiments, the OMT 406 may route the first and second diversityreceive signals to the waveguide filters 408 and 412, respectively,based on the polarization of the signals.

In some embodiments of an antenna diversity system, the main antenna mayprovide the first diversity receive signal to a first receiver on afirst path and the diversity antenna may provide the second diversityreceive signal to a second receiver on a second path.

In step 708, a receiver 416 may receive and downconvert the firstdiversity receive signal from an RF frequency to a first frequency. Insome embodiments, the first diversity receive signal may be provided tothe receiver 416 from the waveguide filters 408. The receiver 416 mayprocess (e.g., filter, adjust the gain, adjust phase, and/or remodulatethe first diversity receive signal) as well as downconvert the firstdiversity receive signal. In some embodiments, the first diversityreceive signal may be downconverted to an IF frequency.

In step 710, a receiver 420 may receive and downconvert the seconddiversity receive signal from an RF frequency to a second frequency. Ina manner similar to step 708, the first diversity receive signal may beprovided to the receiver 420 from the waveguide filters 412. Thereceiver 420 may process (e.g., filter, adjust the gain, adjust phase,and/or remodulate the second diversity receive signal) as well asdownconvert the second diversity receive signal.

In some embodiments, the second diversity receive signal may bedownconverted to an IF frequency that is at a different frequency thanthe downconverted first diversity receive signal. For example, the firstdiversity receive signal may be downconverted to 126 MHz and the seconddiversity receive signal may be downconverted to 500 MHz.

In step 712 and 714, the N-plexer 430 may receive the first diversityreceive signal from the receiver 416 via signal path 424 and may receivethe second diversity receive signal from the receiver 420 via signalpath 428. The N-plexer 430 may provide both signals to the single cable432 to provide the signals to a modem or other unit.

Those skilled in the art will appreciate that the cable maysimultaneously propagate multiple signals at different frequencies. TheN-plexer 430 of the ODU 400 and the N-plexer 602 of the IDU 600, forexample, may be configured to route signals from the single cable 432based on the different frequencies of the propagating signals. Forexample, the single cable 432 may simultaneously propagate six or moresignals including, for example, two transmit signals to be transmittedby the ODU, two receive signals to be demodulated by the IDU, a powersignal to power the ODU, and a telemetry signal to allow forcommunication between the two units. As a result, few cables between thetwo units may be utilized thereby reducing complexity, saving costs, andreducing ports and cables within the system.

In step 714, the N-plexer 602 of FIG. 6 provides first and seconddiversity receive signals from the cable to first and second signalpaths within the second unit (e.g., IDU 600). The IDU 600 or second unitmay be any unit with a modem (e.g., modem 608). The N-plexer 602 mayprovide the first and second diversity receive signals from the cable tothe first and second signal paths based on the frequencies of thesignals.

In step 716, the modem 608 may demodulate the first and second diversityreceive signals received from the first and second signal paths togenerate the first and second demodulated signals. In some embodiments,the first and second demodulated signal may contain different data. Inother embodiments, one of the two signals is to provide error correctioncaused by distortion, interference, and/or fading conditions. In someembodiments, the modem 608 may provide a single corrected demodulatedsignal, provide two demodulated signals, or provide a single demodulatedsignal with information from both receive signals (e.g., for increasedcapacity).

In various embodiments, the modem 608 may downconvert the first andsecond diversity receive signals. In one example, the modem 608 maydownconvert the signals to a baseband frequency or any frequency. Insome embodiments, the modem 608 and/or the IF-BB converter 610 maydownconvert the first and second diversity signals (or the first andsecond demodulated signals.

Those skilled in the art will appreciate that the modem 608 may furtherformat the first and second demodulated signals to a form that may beutilized by the customer premises equipment. For example, the modem 608may prepare the first and second demodulated signals for Ethernet orTDM.

In step 718, the downconverted signal(s) are provided to customerpremises equipment.

Those skilled in the art will appreciate that the steps of FIG. 7 may beperformed in any order. Further, any of the steps or any combination ofsteps may be performed simultaneously with other steps or othercombination of steps.

FIG. 8 is a flow diagram for transmitting two diversity transmit signalsover a split mount system utilizing a single cable in some embodiments.In step 802, the IDU 600 receives first and second transmit data fromcustomer premises equipment. Those skilled in the art will appreciatethat any unit or modem may receive the first and second transmit data.In some embodiments, a single data signal from the customer premisesequipment may be split into the first and second transmit data.

In step 804, the modem 608 modulates the first and second transmit datato first and second diversity transmit signals and provides the signalsto first and second signal paths. In some embodiments, there may be foursignal paths between the N-plexer 602 and the modem 603 which may allowfor propagation of two receive signals and two transmit signals ondifferent signal paths. The N-plexer 602 may be coupled to any number ofsignal paths including, for example, additional signal paths for powerand/or telemetry.

In various embodiments, the modem 608 upconverts the frequencies of thetwo diversity transmit signals to two different IF frequencies. (e.g., afirst transmit frequency may be upconverted to 311 MHz while the secondtransmit frequency may be upconverted to 700 MHz). For example, themodem 608 may adjust the frequency of the first and/or second transmitsignals to make the frequencies different from one another and/ordifferent from signals that may propagate on the cable 432.

In some embodiments, the IF-BB converter 610 upconverts the twodiversity transmit signals to one IF frequency or two different IFfrequencies.

In step 806, the N-plexer 602 provides first and second diversitytransmit signals from the modem to the cable 432. In step 808, theN-plexer 602 also provides power and/or telemetry data from the secondunit (e.g., IDU 600) to the cable 432.

In step 810, the N-plexer 430 of the ODU 400 may provide the first andsecond diversity transmit signals from the cable 432 to the seventh andeighth signal paths of the ODU 400. As discussed herein, the N-plexer430 may route the signals based on their distinct frequencies.

In step 812, the N-plexer 430 may provide the power signal and telemetrysignal to the fifth and sixth signal paths, respectively, of the ODU 400based on the distinct frequencies of the power and telemetry signals.

In step 814, the transmitter 414 may upconvert the first diversitytransmit signal from the fifth signal path to a transmit RF frequency.Similarly, in step 816, the transmitter 418 may upconvert the seconddiversity transmit signal from the sixth signal path to the RFfrequency.

In step 818, the upconverted first and second diversity transmit signalsare directed to at least one antenna. For example, the waveguide filters408 may receive the first upconverted diversity transmit signal from thetransmitter 414 and provide the signal to the OMT 406. Similarly, thewaveguide filters 412 may receive the second upconverted diversitytransmit signal from the transmitter 418 and provide the signal to theOMT 406. The OMT 406 may horizontally polarize the upconverted firsttransmit signal and vertically polarize the upconverted second transmitsignal.

In step 820, the at least one antenna (e.g., antenna 402) may transmitthe orthogonally polarized transmit signals.

Those skilled in the art will appreciate that the steps of FIG. 8 may beperformed in any order. Further, any of the steps or any combination ofsteps may be performed simultaneously with other steps or othercombination of steps.

The above-described functions may be performed in hardware. In oneexample, the functions may be performed by one or morefield-programmable gate arrays (FPGAs), discrete hardware, and/or one ormore application-specific integrated circuits (ASICs).

Further, one or more functions may be stored on a storage medium such asa computer readable medium. The instructions can be retrieved andexecuted by a processor. Some examples of instructions are software,program code, and firmware. Some examples of storage medium are memorydevices, tape, disks, integrated circuits, and servers. The instructionsare operational when executed by the processor to direct the processorto operate in accord with some embodiments. Those skilled in the art arefamiliar with instructions, processor(s), and storage medium.

Various embodiments are described herein as examples. It will beapparent to those skilled in the art that various modifications may bemade and other embodiments can be used without departing from thebroader scope of the present invention. Therefore, these and othervariations upon the exemplary embodiments are intended to be covered bythe present invention(s).

1. A system, comprising: an N-plexer configured to receive from a cablea first receive signal having a first receive frequency, the firstreceive signal being generated from a first diversity receive signalreceived by at least one antenna, receive from the cable a secondreceive signal having a second receive frequency different than thefirst receive frequency, the second receive signal being generated froma second diversity receive signal received by the at least one antenna,the first diversity receive signal and the second diversity receivesignal having signal diversity, provide the first receive signal to afirst signal path based on the first receive frequency, and provide thesecond receive signal to a second signal path based on the secondreceive frequency; and a modem coupled to the N-plexer and configured toreceive the first receive signal from the first signal path, receive thesecond receive signal from the second signal path, and demodulate thefirst receive signal and the second receive signal to generate a datasignal.
 2. The system of claim 1, wherein the first receive signal isredundant to the second receive signal.
 3. The system of claim 1,wherein the first receive signal and the second receive signal providedifferent portions of the data signal.
 4. The system of claim 1,wherein: the system is part of an indoor unit; the cable couples theindoor unit to an outdoor unit; and the outdoor unit is coupled to theat least one antenna.
 5. The system of claim 1, wherein the modem isfurther configured to receive a second data signal for wireless radiofrequency transmission by the at least one antenna, modulate the seconddata signal to generate a transmit signal for wireless radio frequencytransmission by the at least one antenna, and forward the transmitsignal to a first signal path; and the N-plexer is further configured toprovide the transmit signal to the cable at a third frequency.
 6. Amethod, comprising: receiving by an N-plexer from a cable a firstreceive signal having a first receive frequency, the first receivesignal being generated from a first diversity receive signal received byat least one antenna; receiving by the N-plexer from the cable a secondreceive signal having a second receive frequency different than thefirst receive frequency, the second receive signal being generated froma second diversity receive signal received by the at least one antenna,the first diversity receive signal and the second diversity receivesignal having signal diversity; providing by the N-plexer the firstreceive signal to a first signal path based on the first receivefrequency; providing by the N-plexer the second receive signal to asecond signal path based on the second receive frequency; receiving by amodem the first receive signal from the first signal path; receiving bythe modem the second receive signals from the second signal path; anddemodulating by the modem the first receive signal and the secondreceive signal to generate a data signal.
 7. The method of claim 6,wherein the first receive signal is redundant to the second receivesignal.
 8. The method of claim 6, wherein the first receive signal andthe second receive signal provide different portions of the data signal.9. The method of claim 6, wherein: the N-plexer and the modem are partof an indoor unit; the cable couples the indoor unit to an outdoor unit;and the outdoor unit is coupled to the at least one antenna.
 10. Themethod of claim 6, further comprising: receiving by the modem a seconddata signal for wireless radio frequency transmission by the at leastone antenna; modulating by the modem the second data signal to generatea transmit signal for wireless radio frequency transmission by the atleast one antenna; forwarding by the modem the transmit signal to afirst signal path; and providing by the N-plexer the transmit signal tothe cable at a third frequency.
 11. A system, comprising: a modemconfigured to receive a data signal for wireless radio frequencytransmission by at least one antenna, modulate at least a first portionof the data signal to generate a first transmit signal, the firsttransmit signal generated for wireless radio frequency transmission bythe at least one antenna using a first signal diversity, modulate atleast a second portion of the data signal to generate a second transmitsignal, the second transmit signal generated for wireless radiofrequency transmission by the at least one antenna using a second signaldiversity, the first signal diversity being diverse from the secondsignal diversity, forward the first transmit signal to a first signalpath, and forward the second transmit signal to a second signal path;and an N-plexer coupled to the first signal path and to the secondsignal path, and configured to provide the first transmit signal to acable at a first frequency, and provide the second transmit signal tothe cable at a second frequency different than the first frequency. 12.The system of claim 11, wherein the first portion and the second portionare the same portion.
 13. The system of claim 11, wherein the firstportion is different than the second portion.
 14. The system of claim11, wherein the first frequency and the second frequency areintermediate frequencies between baseband and radio frequency.
 15. Thesystem of claim 11, wherein the N-plexer is further configured toreceive from the cable a first receive signal at a third frequencydifferent than the first and second frequencies, the first receivesignal being generated from a first diversity receive signal received bythe at least one antenna, receive from the cable a second receive signalat a fourth frequency different than the first, second and thirdfrequencies, the second receive signal being generated from a seconddiversity receive signal received by the at least one antenna, the firstdiversity receive signal and the second diversity receive signal havingsignal diversity, provide the first receive signal to the first signalpath based on the third frequency, and provide the second receive signalto the second signal path based on the fourth frequency; and the modemis further configured to receive the first receive signal from the firstsignal path, receive the second receive signal from the second signalpath, and demodulate the first receive signal and the second receivesignal to generate a second data signal.
 16. A method, comprising:receiving by a modem a data signal for wireless radio frequencytransmission by at least one antenna; modulating by the modem at least afirst portion of the data signal to generate a first transmit signal,the first transmit signal generated for wireless radio frequencytransmission by the at least one antenna using a first signal diversity;modulating by the modem at least a second portion of the data signal togenerate a second transmit signal, the second transmit signal generatedfor wireless radio frequency transmission by the at least one antennausing a second signal diversity, the first signal diversity beingdiverse from the second signal diversity; forwarding by the modem thefirst transmit signal to a first signal path; forwarding by the modemthe second transmit signal to a second signal path; providing the firsttransmit signal to a cable at first frequency; and providing the secondtransmit signal to the cable at a second frequency different than thefirst frequency.
 17. The method of claim 16, wherein the first portionand the second portion are the same portion.
 18. The method of claim 16,wherein the first portion is different than the second portion.
 19. Themethod of claim 16, wherein the first frequency and the second frequencyare intermediate frequencies between baseband and radio frequency. 20.The method of claim 16, further comprising: receiving by the N-plexerfrom the cable a first receive signal at a third frequency differentthan the first and second frequencies, the first receive signal beinggenerated from a first diversity receive signal received by the at leastone antenna; receiving by the N-plexer from the cable a second receivesignal at a fourth frequency different than the first, second and thirdfrequencies, the second receive signal being generated from a seconddiversity receive signal received by the at least one antenna, the firstdiversity receive signal and the second diversity receive signal havingsignal diversity; providing by the N-plexer the first receive signal tothe first signal path based on the third frequency; providing by theN-plexer the second receive signal to the second signal path based onthe fourth frequency; receiving by the modem the first receive signalfrom the first signal path; receiving by the modem the second receivesignal from the second signal path; and demodulating by the modem thefirst receive signal and the second receive signal to generate a seconddata signal.